I had a good look, and whats on the main "boy" scan, doesnt seem to be on the 3d one?? I'm gonna say cord... and give a little hope to I, and say she is getting a sister!!
I dunno if the 3d one really shows low enough?

Mind you when you look at the scanned in print out one, the cord does appear to run down between the legs..... hmmmmmm Im happy for it to be a boy but happier if it is a girl LOL